Process of controlling the rate of discharge of liquid suspensions from containers



April 14, 1953 F J FONTEIN 3 41 PROCESS OF CONTROLLING THE RATE OF DISCHARGE OF LIQUID SUSPENSIONS FROM CONTAINERS Filed Oct. 9, 1946 40 QrWQ/WYM Hear 11 51: 221321 58 6: A p q-wmm lei/k W35.

Patented Apr. 14, 1953 PROCESS OF CONTROLLING THE RATE OF DISCHARGE OF LIQUID SUSPENSIONS FROM CONTAINERS Freerk J. Fontein, Heerlen, Netherlands, assignor. to De Directie van de Staatsmijnen in Limburg", ,1 9 h r an a v l 7 N Application October 9, 1946, Serial No. 702,308

4 Claims.

This invention relates to methods for controlling the rate of flow of fluid materials.

There are numerous instances in which it is desirable to possess some method by which the rate'of flow of fluid materials to or from consion so that, if the solids content of the suspension is low, only a small amount of the suspension is drawn off from the receiver, whereas, if the concentration of the Solids in the suspension is high, a larger amount of the fluid material must 'be withdrawn. Other numerous situations exist in which it is desirable or essential that the rate of flow of fluid materials be controlled by some positive means not employing moving mechanical parts.

Heretofore, the regulation of fluid flow has necessitated the use of flow controlling means such as valves, flexible diaphragm restrictors o other apparatus in which the fluid flow is regulated by the constriction of the fluid-stream by 'abutments or other COIlStIiCting, --moving elements.

Various disadvantages are associated with the use of these prior art devices forfluid control, particularly with regard to suspensions of solid materials. Thus, where valves or comparable units are used for the fluid control, as the valve is throttled to restrict the magnitude of the fluid stream, the effective diameter of the fluid conduit becomes smaller with increasin opportunity and likelihood for the conduit to become blocked by the solid material in the suspension.

A principal object of this invention is the provision of new method for the control of th rate of flow. of fluid materials. A further bject s the provision ofmeans whereby the flow of fluid material may be controlled without the use of moving mechanical parts. A still further object is the provision of a flow control device with inlet and discharge openings of such size that blocking of these openings by large particles in suspensions flowing therethrough is substantially impossible. Another object is the provision of apparatus for the control of fluid flow which is automatically 2 responsive to the magnitude of the fluid flow entering the control unit. Still further objects and the entire scope of practicability of this invention will become apparent from the detailed discussion given hereinafter.

These objects are accomplished according to the present invention by a process which com prises causing the flow of the fluid material which it is desirable to control to flow tangentially into a circular path of relatively small radius, so that the entrance of further material into this circular path is restricted by the centrifugal force of the fluid material flowing in the circular path and discharging the fluid material centrally and axially of the circular path.

This invention provides new apparatus for accomplishing such a procedure, the details of which may be most readily comprehended by reference to the attached more or less schematic drawing, in which:

Figure 1 is a schematic side view of one embodiment of this apparatus.

Figure 2 is a sectional view of the new control unit of the apparatus shown in Figure 1 taken along the line 2-2.

Figure 3 is a side view partly in section of a modified form of apparatus incorporating the flow control device of this invention.

Referrin in detail to the illustrations, there is shown the flow control device I0 connected to a fluid material container .12.

The flow control device!!! is extremely simple in construction and incorporates no moving parts. This device consists of a cylindrical chamber l4 having end plates 16 and I8. Th end plate 16 is provided with an opening 20 situated substantially in the center of the circular plate.

The control device I0 is further provided with an inlet pipe 24 which leads tangentially into the cylindrical chamber 14.

The flow control unit It] is connected to the container l2 by connecting means consisting of a valve 26 and a pipe 28. The valve 26 is flanged for attachment to the flanged end 30 of the le pipe 24.

The opening 20 which is positioned centrally and axially of the cylindrical chamber l4, serves as a discharge port for fluid material flowing through the control unit H].

A modified form of the control unit is illustrated in Figure 3. There is sown in this illustration the control unit 32 connected to afluid material container 12. .Theflow control unit .32, as in thecase of the unit l0, shown in Figures 1 and .2, possesses the. essential elements of the right angles so that when connected by the flange 40 to the vertical discharge pipe 28 of the container l2, the axis of the dischargeport .36 is in a vertical position, in contrast-to ,zthfe hori zontal position of the axis of discharge port 20 of the control unit ID described above With these details of this flqw out in mind, the mode of operation ofthddefiii may be readily comprehended.

The effect of the device is,'7that"if the Iviscosity't of the fluid is low, the amount of fluid discharged is low and, if the viscosity is high, the

amount of thefluid discharged is high, Thus, if th viscosity is" 16w, "th' tangential iveldcity "ichthe flui'dfcomes mto thedevic'e will w the other i'han'dQ' thebentrifugal forces which are generatedfand' which restrict the final outputout of the'deviceare high-clue to 'the frictional forces betweenthe' different strata, which are formed concentrically in the device. The tangentialvelocity of these strata tends w increase with decreasing radius? Due to thesehigh centrifugal forces, the pressure at the input of the device is high andfthus; the pressure difference between container .and'devicefw hich'finally governs the rate 'of fiow is low, with'the effect that the amount 'of' fluid which is discharged by the device is low?" On the other hand; if" the viscosity-is high, thefrictional forces between the different strata are high. 'So'there is only a'moderate possi b'ility for the tangential" velocity to'increase with decreasing radius The lower this-tangential velocity, the lower the "centriiugalforces which are generated,

"*3 -'I f"the centrifugal forces-"due to: this high viscosity arelow, the pressure in the devi'ce'will be low and, hence, the pressure difference between device and container'is high and the amount of fluid, discharged by the device'is high;

The operation of the process of this'inventiori'is further cor'nprehendable-fromthe following' illustrative example.

g E am? 5;] -A suspension storagetank for-a co al---washing pIa-ntis provided at i-tsbase outlet with allow control devicept this inventions-This: control device has an inlet DiPE'Ofr'Fgil'lGh inside diameter and a single discharge port of the same diameter. The inside diameter 2 of -the cylindrical chamber of the control unitis 1% inches and the height of the chamberv is 'inch.-

With acoal separating--unit operating with a suspensionof loess in water and the storage tank containing a-suspension with a concentration of 10% by weight of the solidmaterial; the flow control device permits 0.32 cubic meter per hour of the suspension to discharge; At thisconcentration' of suspension, 'the contraction coemcient In another case in which the concentration of the loess susp'ension is"41% byweight of solid,

'the control permits' 054' cubic meter per hour to'be' discharged which"coresp'onds to a condevice operates to permit "larger quantities of the liquid suspension" of high solids content to acter, e.'g., finely divided solid matter suspended .in .waten,

4 be discharged than in the case of the lower concentration suspension, as is desired for proper operation of the separating apparatus.

It is possible to control the flow of many types of materials by means of the present process and apparatus fluids, such as .pure' liquids may be controlled or fluid materials, such as suspensions of solid materials in liquids or gases in liquids may be controlled. The term fluid material,.-as usedherein and the following claims, is'int'ended to include all of these types of materials, while the term liquid material, as used herein, means those materials which are predominantly liquid in character, as opposed to those which are predominantly gaseous in char- Since many and various modifications to the present invention will become apparent to those skilled in the art from the detailed description given 'h'erein;;it.is to be understood" that this invention is to be "limited only in accordance with the following claims."

Iclaim: i The process "ofcontrolling the rate of discharge of liquid suspensions from containers so that the rate of discharge increases with an increasein the solids content of the suspension which comprises flowing the suspension from the container tangentially into, a circular path of relatively small radius, whereby the rate of discharge is restricted by the centrifugal force of the suspension flowing said circular path and, thereafter, discharging the suspension from the locus ofv its circular flow axially of the circular path.

2. The process of continuously and automatically controlling hydraulically the'quantity of a liquid dispersion of varying solids content emitted from a container whereby the quantity emitted-increases upon increase of the solids content and decreases upon decrease ofthe solids content, :which'comprises flowing of liquid suspension from the container through a confined passage and emitting it tangentially into a body to establish its rotation, with the speed of rotation of the liquidsuspension being determined by the solids content of the suspension, such speed generating centrifugal forces within the body which exert a back pressure on the suspension being emitted fromthe conflnedpassage, and discharging axially. from the .body a stream of-suspension in such. hydraulically controlled quantity.,, -.3..A process as. claimed in claim 1, wherein said suspension is discharged along a horizontal axis.

4. A process as claimed in claim 1, wherein said suspension is discharged along a vertical axis.

' 'FREERK J. FONTElN.

References Cited in the file of this patent UNITED STATES PATENTS Date Number Name 491,354 Jett Feb. 7, 1893 1,293,108 Judson; Feb. 4, 1919 1,517,598 Stevensen. Dec. 2, 1924 1,710,832 Mart Apr. 30, 1929 1,839,616' Thoma Jan. 5, 1932 2,135,582 Kohler Nov. 8, 1938 2,229,601 Park' Jan. 21, 1941 .'2.'304.272 Mueller Dec. 8. 1942 

